1. Field of the Invention
The present invention pertains to a double clutch assembly, comprising a first clutch area for the optional production of a first torque-transmitting connection between a drive element and a first driven element, and a second clutch area for the optional production of a second torque-transmitting connection between the drive element and a second driven element.
2. Description of the Related Art
Double clutch assemblies of this type are used, for example, in conjunction with variable gear transmissions which have two transmission input shafts. Different gear stages can be engaged, depending on which of the transmission input shafts is in the torque-transmitting path after actuation of the associated clutch area. To implement the engagements and disengagements of the clutch, it is known in double clutch assemblies of this type that each clutch area can have its own, separate engaging/disengaging mechanism, so that, depending on the actuation or activation of one of the engaging/disengaging mechanisms, one of the clutch areas can be disengaged while the other is or becomes engaged. This leads to a relatively complicated design, however, because the two engaging/disengaging mechanisms, such as engaging/disengaging piston-cylinder assemblies, must be installed in a small space and thus staggered radially, for example, with respect to each other.
The object of the present invention is to improve the double clutch assembly of the general type in question so that, with a simpler design for executing engagements and disengagements, the various clutch areas can be activated in a simplified manner.
This object is accomplished according to the invention by a double clutch assembly, comprising a first clutch area for the optional production of a torque-transmitting connection between a drive element and a first driven element and a second clutch area for the optional production of a torque-transmitting connection between the drive element and a second driven element.
The double clutch assembly according to the invention has a common engaging/disengaging mechanism, by means of which the first and the second clutch areas can be actuated to produce or to nullify the torque-transmitting condition.
According to the invention, therefore, the principle of providing a separate engaging/disengaging mechanism for each clutch area, these separate mechanisms then also being actuated separately, is abandoned. Instead, a single mechanism of this type is provided, which, depending on how it is actuated, can have the effect either of engaging one of the clutch areas while disengaging the other or of keeping both clutch areas in a state of partial torque transmission. This considerably simplifies both the design of a clutch assembly of this type and the measures required to actuate the clutch.
In accordance with the invention, it is then also provided preferably that, when one of the clutch areas has been actuated by the engaging/disengaging mechanism to produce the torque-transmitting condition, the other clutch area is actuated to nullify the torque-transmitting condition.
In the double clutch assembly according to the invention, a force storage element can be provided, by means of which at least one of the clutch areas is or can be held under pretension in its torque-transmitting condition.
For the execution of engaging and disengaging operations of the various clutch areas, furthermore, a force-generating mechanism is preferably provided to generate an actuating force, by means of which at least one of the clutch areas can be brought into its torque-transmitting condition.
To minimize the effort required to actuate the force-generating mechanism, it is proposed that, by means of the force-storage element, one of the clutch areas is pretensioned in its torque-transmitting condition, and that, by means of the force-generating mechanism, the force-storage element can be moved to nullify the torque-transmitting condition of the one clutch area while producing the torque-transmitting condition of the other clutch area. The clutch assembly is thus always kept under pretension by the force-storage element in such a way that one of the clutch areas is engaged, whereas, in order to engage the other clutch area, the force-generating mechanism must be energized.
In another advantageous embodiment of the invention, it can be provided that the force-storage element is a bistable force-storage element, that the force-storage element can be switched from one of its stable states to the other by the force-generating mechanism, and that, in each of the two stable states, one of the clutch areas is held under pretension in its torque-transmitting condition by the force-storage element. In this variant, either one of the clutch areas can be held under pretension in its engaged position by the force-storage element when the force-storage element, under the action of the force-generating mechanism, is brought into the appropriate stable position.
In another, alternative design variant, a force-transmitting lever assembly can be provided, by means of which the actuating force can be transmitted from the force-generating mechanism to the first clutch area and the second clutch area.
The first clutch area preferably has a first friction surface, which can be brought to rest against a first clutch disk assembly; the second clutch area has a first friction surface which can be brought to rest against a second clutch disk; and an intermediate disk assembly with a second friction surface for the first clutch area and a second friction surface for the second clutch area is provided for the first and second clutch areas.
In order to produce the torque-transmitting condition of one of the clutch areas and to nullify the torque-transmitting condition of the other clutch area in the case where the second friction surfaces of the first and second clutch areas are essentially fixed, and to switch easily from one of the two clutch areas to the other, the first friction surface of the one clutch area can be moved toward the second friction surface of the one clutch area, and the first friction surface of the other clutch area can be moved away from the second friction surface of this other clutch area. It is then advantageous in this case for a component carrying the first friction surface of the first clutch area and a component carrying the first friction surface of the second clutch area to be connected to the engaging/disengaging mechanism for movement with respect to the associated second friction surfaces.
As an alternative to produce the torque-transmitting condition of one of the clutch areas and to nullify the torque-transmitting condition of the other clutch area in the case where the friction surfaces of the first and second clutch areas are essentially fixed, and to easily produce or nullify the torque-transmitting condition, the second friction surface of the one clutch area can be moved toward the first friction surface of the one clutch area, while the second friction surface of the other clutch area can be moved away from the first friction surface of the other clutch area.
To minimize any change in the operating characteristic of the double clutch assembly even after prolonged periods of operation, the double clutch assembly according to the invention preferably also has a wear compensation assembly to compensate for the wear which occurs in the first clutch area and/or in the second clutch area.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.